scholarly journals Nature of the coordination bond in metal complexes of substituted pyridine derivatives. IV. Skeletal vibration spectra and the substituent effect upon the coordination bond of the pyridine complex of zinc(II) ion

1969 ◽  
Vol 47 (24) ◽  
pp. 4589-4597 ◽  
Author(s):  
Patrick T. T. Wong ◽  
D. G. Brewer
Keyword(s):  
Previous Investigation ◽  
Copper Complexes ◽  
Far Infrared ◽  
Coordination Bond ◽  
Pyridine Derivatives ◽  
Normal Coordinate ◽  
Absorption Bands ◽  
Pyridine Complex ◽  
Far Infrared Spectra ◽  
Coordinate Treatment

Far infrared spectra of the complexes Zn(pyridine)2X2, where X = Cl or Br, have been investigated in the region 350–20 cm−1. Eight infrared-active skeletal modes of these complexes have been observed, and a tentative assignment of these absorption bands has been made. The previous investigation of the effect of substituents upon the coordination bond of the copper–pyridine complex has been extended to the zinc–pyridine complex in the present paper. It was found that the relative zinc–pyridine bond strength, affected by the substituents, is determined by both the relative σ-contribution and π-contribution to the bond, rather than mainly by the σ-contribution as in the system of copper complexes. The force constants associated with the zinc–pyridine coordination bond of a series of 4-substituted pyridine complexes have been calculated by a normal coordinate treatment described in previous papers in this series.

The nature of the coordination bond in metal complexes of substituted pyridine derivatives. III. 4-Methylpyridine complexes of some divalent transition metal ions

1968 ◽  
Vol 46 (20) ◽  
pp. 3137-3141 ◽  
Author(s):  
D. G. Brewer ◽  
P. T. T. Wong ◽  
M. C. Sears
Keyword(s):  
Infrared Spectroscopy ◽  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Ions ◽  
Coordination Bond ◽  
Pyridine Derivatives ◽  
Normal Coordinate ◽  
Substituted Pyridines ◽  
Solid Complexes ◽  
Nitrogen Bond

Previous papers in this series investigated the nature of the coordination bond in copper(II) and zinc(II) complexes of 4-substituted pyridines by infrared spectroscopy. In this paper, the investigation has been extended to complexes of 4-methylpyridine with cobalt(II), manganese(II), and nickel(II). The geometry of the solid complexes is assigned, and the force constants associated with the metal–nitrogen bond were calculated from a normal coordinate analysis. The validity of the previously introduced Rπ parameter in these systems is discussed.

Far infrared spectra of charge-transfer complexes between iodine and substituted pyridines

1967 ◽  
Vol 297 (1451) ◽  
pp. 440-448 ◽  
Keyword(s):  
Charge Transfer ◽  
Infrared Spectra ◽  
Equilibrium Constants ◽  
Far Infrared ◽  
Charge Transfer Complexes ◽  
Absorption Bands ◽  
Substituted Pyridines ◽  
Stretching Vibration ◽  
Far Infrared Spectra ◽  
Electronic And Steric Effects

Far infrared spectra of charge-transfer complexes between iodine and substituted pyridines, dissolved in cyclohexane, have been measured in the region 20 to 200 cm -1 . Bands have been assigned to the modified iodine molecule stretching vibration near 180 cm -1 , and to the stretching of the intermolecular bond in the range 65 to 95 cm -1 . The shifts of the vibration frequencies, and force constants calculated using a simple valency force field, have been discussed in relation to the mass, electronic and steric effects of substituent groups. Equilibrium constants for the formation of the complex have been determined. From the intensities of the absorption bands, further evidence has been found for a vibronic interaction, leading to a delocalization of the transition moment in the vibrations of the complexes, and to an enhancement of the intensity of absorption.

Structural and Spectroscopic Studies on the Dimeric Complexes of Tris(2-methylphenyl)phosphine With Copper(I) Halides

1994 ◽  
Vol 47 (1) ◽  
pp. 25 ◽  
Author(s):  
GA Bowmaker ◽  
JV Hanna ◽  
RD Hart ◽  
PC Healy ◽  
AH White
Keyword(s):  
Solid State ◽  
Far Infrared ◽  
Spectroscopic Studies ◽  
Mixed Ligand ◽  
Acetonitrile Solution ◽  
Normal Coordinate ◽  
Dimeric Complexes ◽  
Copper Coordination ◽  
Binuclear Species ◽  
Far Infrared Spectra

1:1 adducts of the copper(I) halides, CuX (X = Cl, Br, I), with the sterically hindered ligand tris (2-methylphenyl) phospine [P(o- tol )3] have been synthesized as crystalline dihalo -bridged centrosymmetric binuclear species; six compounds have been characterized by solid-state CP-MAS n.m.r. and far-infrared spectroscopy and by room-temperature single-crystal X-ray structure determination. For X = Cl , the dimeric complex. [P(o- tol )3CuCl]2, with three-coordinate copper atoms has been obtained from acetonitrile solution. Similar dimeric complexes for X = Br and I were obtained from toluene solution, the iodide adduct incorporating cocrystallized toluene. The X = Br and I complexes crystallized from acetonitrile solution yield mixed- ligand four-coordinate copper(I) dimers, [( MeCN )P(o- tol )3CuX]2, the iodide as a 2MeCN solvate. An additional crystalline phase incorporating crystallographically independent molecules of both the three-coordinate dimer and the four-coordinate mixed- ligand dimer has also been characterized for X = Br. Solid-state 31P CP-MAS n.m.r. spectra of the complexes at B = 7.05 T show well resolved asymmetric quartets with a ∆v3/∆v1 of 1.4 for the PcuX2 complexes and 1.1-1.2 for the PcuX2N complexes; these results reflect the geometric and bonding changes in the copper coordination sphere. Far-infrared spectra of the complexes show two strong halogen-sensitive bands, with a wavenumber separation of 30-40 cm-1, which have been assigned to copper-halogen stretching modes v( CuX ), this assignment being supported by a normal coordinate analysis on the Cu2X2 core.

Vibrational and electronic spectra of new liposoluble metalloporphyrins in a nonpolar noncoordinating solvent

1991 ◽  
Vol 69 (7) ◽  
pp. 1070-1079 ◽  
Author(s):  
Michel Ringuet ◽  
Denis Girard ◽  
Camille Chapados
Keyword(s):  
Experimental Data ◽  
Infrared Spectroscopy ◽  
Structural Characteristics ◽  
Electronic Spectroscopy ◽  
Far Infrared ◽  
Covalent Radius ◽  
Far Infrared Spectroscopy ◽  
Normal Coordinate ◽  
Vibrational Bands ◽  
Far Infrared Spectra

A new liposoluble porphyrin, 2,7,12,17-tetrahexyl-3,8,13,18-tetramethylporphin(THTMP), and its complexes with divalent (Mg, Co, Ni, Cu, Zn, Cd, Hg) and trivalent (Mn, Fe) metals have been synthesized. The electronic, infrared, and far-infrared spectra of these compounds were obtained in the same nonpolar, noncoordinating solvent, CCl4. After comparison with the experimental data and the results of normal coordinate analyses from the literature, the assignment of the vibrational bands of THTMP and its complexes is made. Some correlations between the shifts of the metal sensitive bands in the diffferent regions and the structural characteristics of the porphyrin complexes are reported. Some emphasis is made on the magnesium complex in relation to chlorophyll. Key words: Metalloporphyrin, porphyrin, infrared spectroscopy, far-infrared spectroscopy, electronic spectroscopy, nitrogen-metal bond, covalent radius, reduced mass.

The nature of the coordination bond in metal complexes of substituted pyridine derivatives. V. 4-Methylpyridine complexes of Zn(II), Cd(II), and Hg(II)

1970 ◽  
Vol 48 (24) ◽  
pp. 3786-3789 ◽  
Author(s):  
M. C. Sears ◽  
W. V. F. Brooks ◽  
D. G. Brewer
Keyword(s):  
Force Field ◽  
Metal Complexes ◽  
Field Model ◽  
Coordination Bond ◽  
Pyridine Derivatives ◽  
Divalent Ions ◽  
Normal Coordinate ◽  
Valence Force ◽  
Valence Force Field ◽  
Zinc Cadmium

In this paper, an attempt is made to interpret the π-bonding between a 4-methylpyridine ligand and the divalent ions of zinc, cadmium, and mercury, using the previously introduced Rπ parameter. To do this, the ν12 mode in the complexes is assigned and confirmed by a normal coordinate analysis based on a valence force field model.

Far infrared spectra of olefin-Pt(II) complexes. Normal coordinate analysis of Zeise's salt

1967 ◽  
Vol 22 (1-4) ◽  
pp. 80-98 ◽  
Author(s):  
Jaime Pradilla-Sorzano ◽  
John P. Fackler
Keyword(s):  
Infrared Spectra ◽  
Far Infrared ◽  
Normal Coordinate Analysis ◽  
Normal Coordinate ◽  
Far Infrared Spectra
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